Flubendiamide is a commonly used pesticide with low water solubility and a high organic carbon sorption constant,causing it to adhere to soil particles and negatively impact soil ecosystems.First,chili plant stems,typ...Flubendiamide is a commonly used pesticide with low water solubility and a high organic carbon sorption constant,causing it to adhere to soil particles and negatively impact soil ecosystems.First,chili plant stems,typically discarded after the harvest season,represent an abundant local biomass resource with significant potential for utilization,and were converted into biochar through pyrolysis.Here,we describe the synthesis of biochar modified with iron and chitosan to increase the diversity of functions and surface functional groups of biochar.The resulting chitosan-modified magnetic biochar(CMBC)presents a full range of functional groups of chitosan and iron oxide as shown by Fourier-transform infrared spectroscopy.The correlation between flubendiamide concentration and the dose of biochar on adsorption was explored.The flubendiamide adsorption efficiency of CMBC(1%mass ratio of soil)reached 68.03%in 90 min.The highest adsorption capacity achieved was 0.95 mg·g^(−1).The flubendiamide adsorption mechanism by CMBC can be described with a pseudo-second-order kinetic model.The experiment data closely fit a Freundlich isotherm model(R^(2)=0.998),and the low residual sum of squares values demonstrate the high model applicability.In this study,we present a comprehensive overview of pesticides,alongside kinetic and isotherm model studies of flubendiamide adsorption by CMBC.We emphasize the potential of modified biochar to enhance environmental remediation applications.展开更多
Iron-based perovskite-type compounds modified by Ru were prepared through sol-gel process to study its catalytic activity of NOx direct decomposition at low temperature and evaluate the conversion of NO under the expe...Iron-based perovskite-type compounds modified by Ru were prepared through sol-gel process to study its catalytic activity of NOx direct decomposition at low temperature and evaluate the conversion of NO under the experimental conditions. The catalytic activity of La 0.9Ce 0.1Fe 0.8-nCo 0.2RunO3 （n=0.01,0.03,0.05,0.07,0.09）series for the NO, NO-CO two components, CO-HC-NO three components were also analyzed. The catalytic investigation evidenced that the presence of Ru is necessary for making highly activity in decomposition of nitric oxide even at low temperature（400 ℃）and La 0.9Ce 0.9Fe 0.75Co 0.2Ru 0.05O3 （n=0.05） has better activity in all the samples, the conversion of it is 58.5%. With the reducing gas（CO,C3H6）added into the gas, the catalyst displayed very high activity in decomposition of NO and the conversion of it is 80% and 92.5% separately.展开更多
Antibiotic pollution has become a global eco-environmental issue.To reduce sulfonamide antibiotics in water and improve resource utilization of solid wastes,phosphogypsummodified biochar composite(PMBC)was prepared vi...Antibiotic pollution has become a global eco-environmental issue.To reduce sulfonamide antibiotics in water and improve resource utilization of solid wastes,phosphogypsummodified biochar composite(PMBC)was prepared via facile one-step from distillers grains,wood chips,and phosphogypsum.The physicochemical properties of PMBCwere characterized by scanning electron microscope(SEM),Fourier transform infrared spectroscopy(FTIR),Zeta potential,X-ray diffraction(XRD),etc.The influencing factors,adsorption behaviors,and mechanisms of sulfadiazine(SD)and sulfamethazine(SMT)onto PMBC were studied by batch and fixed bed column adsorption experiments.The results showed that the removal rates of SD and SMT increased with the increase of phosphogypsum proportion,while decreased with the increase of solution pH.The maximum adsorption capacities of modified distillers grain and wood chips biochars for SD were 2.98 and 4.18 mg/g,and for SMT were 4.40 and 8.91mg/g,respectively,which was 9.0–22.3 times that of pristine biochar.Fixed bed column results demonstrated that PMBC had good adsorption capacities for SD and SMT.When the solution flow rate was 2.0 mL/min and the dosage of PMBC was 5.0 g,the removal rates of SD and SMT by modified wood chips biochar were both higher than 50%in 4 hr.The main mechanisms of SD and SMT removal by PMBC are hydrogen bonding,π-πdonor-acceptor,electrostatic interaction,and hydrophobic interaction.This study provides an effective method for the removal of antibiotics in water and the resource utilization of phosphogypsum.展开更多
As an effective conventional absorbent, biochar exhibited limited adsorption ability toward small hydrophobic molecules. To enhance the adsorption capacity, a novel adsorbent was prepared by immobilizing nanoscale zer...As an effective conventional absorbent, biochar exhibited limited adsorption ability toward small hydrophobic molecules. To enhance the adsorption capacity, a novel adsorbent was prepared by immobilizing nanoscale zero-valent iron onto modified biochar（MB） and then the elemental silver was attached to the surface of iron（Ag/Fe/MB）. It＇s noted that spherical Ag/Fe nanoparticles with diameter of 51 nm were highly dispersed on the surface of MB. As the typical hydrophobic contaminant, carbon tetrachloride was selected for examining the removal efficiency of the adsorbent. The removal efficiencies of carbon tetrachloride by original biochar（OB）, Ag/Fe, Ag/Fe/OB and Ag/Fe/MB were fully investigated. It＇s found that Ag/Fe/MB showed higher carbon tetrachloride removal efficiency, which is about 5.5 times higher than that of the OB sample due to utilizing the merits of high adsorption and reduction. Thermodynamic parameters revealed that the removal of carbon tetrachloride by Ag/Fe/MB was a spontaneous and exothermic process, which was affected by solution p H, initial carbon tetrachloride concentration and temperature. The novel Ag/Fe/MB composites provided a promising material for carbon tetrachloride removal from effluent.展开更多
Low organic matter content and high heavy metal levels severely inhibit the anaerobic digestion(AD) of sewage sludge. In this study, the effect of added manganese oxidemodified biochar composite(MBC) on methane produc...Low organic matter content and high heavy metal levels severely inhibit the anaerobic digestion(AD) of sewage sludge. In this study, the effect of added manganese oxidemodified biochar composite(MBC) on methane production and heavy metal fractionation during sewage sludge AD was examined. The MBC could increase the buffering capacity,enhance the methane production and degradation of intermediate acids, buffer the pH of the culture, and stabilize the sewage sludge AD process. The application of MBC positively impacted methane production and the cumulative methane yield increased up to 121.97%,as compared with the control. The MBC addition can improve metal stabilization in the digestate. An optimum MBC dose of 2.36 g was recommended, which would produce up to 121.1 L/kg volatile solids of methane. After the AD process, even though most of the metals accumulated in the residual solids, they could be transformation from the bio-available fractions to a more stable fraction. The total organic-and sulfide-bound and residual fraction content at a 3 g dose of MBC that is 0.12 g/g dry matter were 51.06% and 35.11% higher than the control, respectively. The results indicated that the application of MBC could improve the performance of AD and promote stabilization of heavy metals in sewage sludge post the AD process.展开更多
Compost has been used to stabilise lead (Pb) in soil. However, compost contains a high level of dissolved organic matter (DOM) which may make Pb bioavailable in plant and thereby limiting its effectiveness and applica...Compost has been used to stabilise lead (Pb) in soil. However, compost contains a high level of dissolved organic matter (DOM) which may make Pb bioavailable in plant and thereby limiting its effectiveness and application. Addition of biochar to compost can reduce this effect. Rice husk (RH) and Cashew nut shell (CNS) biochars and compost-modified biochars were used in comparison to compost for stabilizing Pb in lead smelting slag (LSS)-contaminated soil (Pb = 18,300 mg/kg) in Nigeria. Efficiency of Pb stabilisation in control and amended soils was assessed using CaCl2 batch leaching experiment and plant performance. In pot experiments, maize plant was grown on the contaminated soil and on soil treated with minimum and optimum doses of the amendments singly and in combination for 6 weeks. Agronomical and chemical parameters of the plants were measured. CaCl2-extractable Pb in the untreated soil was reduced from 60 mg/kg to 0.55 mg/kg in RHB amended soils and non-detectable in other amended soils. RH-biochar/compost increased plant height, number of leaf and leaf area more than the others. Similarly, at minimum rate, it reduced root and shoot Pb by 91% and 86.0% respectively. Compost-modified rice husk biocharstabilised Pb in lead smelting slag contaminated soil reduced Pb plant uptake and improved plant growth. Lead stabilisation through the use of rice husk biochar with compost may be a green method for remediation of lead smelting slag-contaminated soil.展开更多
In order to reduce the waste of resources and environmental pollution caused by excessive application of chemical fertilizers, improve the utilization rate of fertilizers, and promote the large-scale and high-quality ...In order to reduce the waste of resources and environmental pollution caused by excessive application of chemical fertilizers, improve the utilization rate of fertilizers, and promote the large-scale and high-quality development of the Chinese rose industry. In this experiment, corn stover biochar, phosphoric acid modified biochar and organic fertilizer were used as test materials, and the effects of mixed application of modified biochar and organic fertilizer on the growth and development of Chinese rose as well as soil physicochemical properties were investigated by using the method of pot planting test. The results showed that modified biochar with organic fertilizer had the most significant effect on the enhancement of soil pH, organic matter content and soil carbon-to-nitrogen ratio. After 120 d of planting, modified biochar with organic fertilizer had the most significant effect on the enhancement of plant height and crown width of Chinese rose;both organic fertilizer and modified biochar with organic fertilizer significantly increased the chlorophyll content of Chinese rose. The number of flowers and the number of branches were the highest in the modified biochar with organic fertilizer treatment. In conclusion, the application of modified biochar with organic fertilizer can better improve the soil pH, and increase the soil organic matter content and carbon-to-nitrogen ratio to change the biological traits of Chinese rose. The results of this study provide a theoretical basis for the reduction of chemical fertilizers and the resource utilization of agricultural wastes and guarantee the sustainable development of the cut flower industry.展开更多
Two major problems facing agriculture at present are soil pollution and the disposal of solid wastes generated during plant growth. The method of preparing biochar from solid wastes produced by plants is a means of ma...Two major problems facing agriculture at present are soil pollution and the disposal of solid wastes generated during plant growth. The method of preparing biochar from solid wastes produced by plants is a means of maximizing the use of resources to combat the problem of soil pollution. In this study, we did not choose straw in the traditional sense but the waste branches from grape pruning, which has higher lignin cellulose, as the raw material. The biochar derived from grape branches pyrolyzed at 300˚C for two hours was utilized as a raw material to prepare modified biochar with varying concentrations of phosphoric acid. The adsorption performance and mechanism of Cd<sup>2 </sup> were explored through experiments involving different concentrations, addition amounts, reaction times, kinetic analyses, and isothermal adsorption tests. The findings indicated that the optimal adsorption of Cd<sup>2 </sup> occurred with a 20% phosphoric acid concentration, achieving the highest adsorption rate of 84.62%. At a dosage of 10 g/L, the maximum adsorption capacity reached 7.02 mg/g. The adsorption kinetics and isothermal adsorption of Cd<sup>2 </sup> on biochar modified with 0.2% phosphoric acid (0.2 PB) closely followed the pseudo-first-order kinetics model (R<sup>2</sup> > 0.98) and the Freundlich model (R<sup>2</sup> > 0.97), respectively. This suggests that the adsorption process involves both physical and chemical mechanisms. SEM and FTIR analyses revealed that phosphoric acid modification primarily increased the biochar’s specific surface area and enhanced certain original functional groups. The adsorption process predominantly involved rapid ion diffusion and chemical adsorption, as confirmed by kinetic analysis and isothermal adsorption model analysis. In summary, the adsorption efficiency of 0.2 PB significantly improved, showing potential and feasibility for heavy metal remediation in soil. This supports the environmentally friendly concept of “treating waste with waste”.展开更多
Food waste,owing to its high organic content and moisture,offers a more scientifically sound resource utilization method compared to traditional treatment processes.This study presents a method to convert food waste i...Food waste,owing to its high organic content and moisture,offers a more scientifically sound resource utilization method compared to traditional treatment processes.This study presents a method to convert food waste into nitrogen-doped,modified hydrogel biochar modified food waste hydrogel biochar and investigates its effectiveness in adsorbing humic acid(HA).The modified biochar demonstrates superior adsorption capacity for HA compared to unmodified biochar.The adsorption follows the Langmuir isotherm model(R2=0.999),achieving a maximum adsorp-tion capacity of 49.5 mg/g with RL=0.0013-0.0051(0<RL<1).Furthermore,the adsorption process conforms to a pseudo-first-order model.The mechanism underlying HA adsorption involves the successful modification of food waste hydrogel biochar by 3-Aminopropyltriethoxysilane(APTES).This modification forms Si―R―NH_(3)^(+) on the biochar surface,which interacts with the COOH―groups in HA through hydrogen bonding and coordination bonds.Some unmodified APTES directly adsorbs onto the biochar surface,undergoing condensation and self-assembly to form ladder-like oligomeric siloxane polymers that enhance HA adsorption.展开更多
Chlorite(ClO_(2)^(−)or COI)is used to establish the advanced reduction and oxidation process(AROP).The iron/biochar-based particles(iron-based hydrothermal carbon with hinge-like structure,FebHCs,20 mg/L)can be utiliz...Chlorite(ClO_(2)^(−)or COI)is used to establish the advanced reduction and oxidation process(AROP).The iron/biochar-based particles(iron-based hydrothermal carbon with hinge-like structure,FebHCs,20 mg/L)can be utilized to activate COI(2 mmol/L)to present selective oxidation in removing triphenylmethane derivatives(15 min,90%).The protonation(H+at~102μmol/L level)played a huge role(k-2nd=0.136c-H+−0.014(R^(2)-adj=0.986),and rapp=−0.0876/c-H++1.017(R^(2)-adj=0.996))to boost the generation of the active species(e.g.,high-valent iron oxidizing species(HVI=O)and chlorine dioxide(ClO_(2))).The protonation-coupled electron transfer promoted Fe-substances in Feb/HCs activating COI(the calculated kobs ranging from 0.066−0.285 min^(−1)).The form of ClO_(2) mainly attributed to proton-coupled electron transfer(1e/1H+).The HVI=O was generated from the electron transfer within the coordination complex.Moreover,carbon particles in FebHCs serve as the bridge for electron transfer.The above roles contribute to the fracture and formation of coordination-induced bonds between Lx-FeII/III and ClO_(2)^(−)at phase interface to form AROP.The ultrasonic(US)cavitation enhanced the mass transfer of active species in bulk solution,and the HVI=O and ClO_(2) attack unsaturated central carbon atoms of triphenylmethane derivatives to initiate selective removal.Furthermore,the scale-up experiment with continuous flow(k values of approximately 0.2 min^(−1),COD removal efficiency of approximately 80%)and the reactor with COMSOL simulation have also proved the applicability of the system.The study offers a novel AROP and new insights into correspondingly heterogeneous interface activation mechanisms.展开更多
Nowadays,biochar is well recognized for its multiple promising effects on the soil quality and plant health.However,there are limited studies on the utilization of invasive plants for biochar production.In the present...Nowadays,biochar is well recognized for its multiple promising effects on the soil quality and plant health.However,there are limited studies on the utilization of invasive plants for biochar production.In the present study,silicon(Si)-modified biochar was synthesized from Solidago canadensis L.,an invasive alien plant in southern China,at different pyrolysis temperatures(450,550,and 650℃).The role of biochar in controlling bacterial wilt,improving soil quality and plant health was assessed.The results revealed that Si-modified biochar had higher wilt suppressive effects than unmodified biochar.Si-modified biochar synthesized at 450℃was found to be the most effective in reducing the abundance of R.solanacearum in soil(66.0%)and the incidence rate of bacterial wilt(59.1%).The Si-modified biochar increased soil available Si(58.2%–147.8%),C/N ratio(85.8–105.0%),and cation exchange capacity(19.7–54.5%).Additionally,it also enhanced the abundance of beneficial bacteria in the soil,such as Bacillus(341.7%),Streptomyces(222.0%),Gaiellales(255.4%),and Gaiella(133.3%).These findings suggest that Si-modified biochar derived from the invasive plant Solidago canadensis L.holds promise as a soil additive for disease control.展开更多
Carbon sequestration in farmland is an important pathway to alleviate global warming.Biochar has been considered an excellent material for soil carbon sequestration because of its high stability.How exogenous minerals...Carbon sequestration in farmland is an important pathway to alleviate global warming.Biochar has been considered an excellent material for soil carbon sequestration because of its high stability.How exogenous minerals and pyrolysis temperature regulate the priming effects(PEs)of biochar on soil organic carbon has rarely been studied,relative microbial mechanisms especially the roles of soil bacteria are far from known.Therefore,a series of biochar was prepared by pyrolysis using(13)^C isotope labelled rice straw at temperatures of 300,500,and 700℃with vermiculite modification(VBC300,VBC500,VBC700)and without modification(BC300,BC500,BC700).Incubation experiments were conducted to investigate the PEs of different biochar on the native organic carbon of two types of soil.Results showed that BC300,VBC300,and BC500 induced positive PE,VBC500,BC700,and VBC700 mainly induced negative PE in red soil.All biochar showed negative PE in paddy soil,with PE intensity order of 500℃>700℃>300℃.Biochar caused a shift in the bacterial phyla from copiotrophic to oligotrophic bacteria in red soil,whereas it shifted from the coexistence of copiotrophic and oligotrophic to copiotrophic in paddy soil over time.Biochar promoted the interaction among soil bacterial communities indicated by an increase in the edge number of bacterial networks.The correlation coefficient between PE and bacteria networks’edge number was 0.626 and 0.909 in red soil and paddy soil,respectively.Vermiculite modification weakened the promotion effect of biochar on bacterial community interaction and thus was beneficial for carbon sequestration,especially in red soil.VBC700 had excellent carbon sequestration potential in red soil,whereas that was VBC500 in paddy soil.展开更多
Arsenic(As)is a known carcinogen and naturally occurring semi-metal in soils and in the Earth's crust.Contamination of soils and water with As poses a serious threat to millions of people worldwide due to its heal...Arsenic(As)is a known carcinogen and naturally occurring semi-metal in soils and in the Earth's crust.Contamination of soils and water with As poses a serious threat to millions of people worldwide due to its health hazards and toxicological properties.Hence,devising novel and efficient methods for remediation of contaminated areas has attracted a great deal of interest across the globe.In this study,we investigated the usefulness of synthetic birnessite,goethite,hexadecylpyridinium chloride-modified montmorillonite(HDPC-M),hexadecylpyridinium bromide-modified zeolite(HDPB-Z),and lanthanum(La)-doped magnetic biochar produced from eucalyptus bark(La-Euchar)as adsorbents at 10%dosage for As stabilization in a soil spiked with 1000 mg kg^(-1)As.The effectiveness of the above adsorbents in As immobilization in soil was assessed using single-step extractions with 2 mol L^(-1)HNO_(3)and deionized water,the simplified bioaccessibility extraction test(SBET)method,and sequential extraction with the modified Community Bureau of Reference(BCR)method.Application of the adsorbents shifted the exchangeable fraction of As to more recalcitrant fractions and dramatically reduced the exchangeable fraction by 6%-99%and the extractable amounts with HNO_(3),deionized water,and SBET method by 30%-92%,17%-95%,and 12%-90%,respectively,compared to the unamended control.The immobilizing effects of adsorbents on As decreased in the sequence of birnessite>La-Euchar>goethite>HDPB-Z>HDPC-M.Birnessite exhibited great affinity for As and drastically reduced As extractability by more than 90%in all single extractions.The results revealed that HDPC-M,HDPB-Z,La-Euchar,birnessite,and goethite are promising immobilizing agents for in situ stabilization of As in terrestrial environments.展开更多
基金supported by research funds of Jeonbuk National University in 2024 and partly supported by the National Research Foundation of Korea(NRF-2019R1A2C1006441)from the Ministry of Education.
文摘Flubendiamide is a commonly used pesticide with low water solubility and a high organic carbon sorption constant,causing it to adhere to soil particles and negatively impact soil ecosystems.First,chili plant stems,typically discarded after the harvest season,represent an abundant local biomass resource with significant potential for utilization,and were converted into biochar through pyrolysis.Here,we describe the synthesis of biochar modified with iron and chitosan to increase the diversity of functions and surface functional groups of biochar.The resulting chitosan-modified magnetic biochar(CMBC)presents a full range of functional groups of chitosan and iron oxide as shown by Fourier-transform infrared spectroscopy.The correlation between flubendiamide concentration and the dose of biochar on adsorption was explored.The flubendiamide adsorption efficiency of CMBC(1%mass ratio of soil)reached 68.03%in 90 min.The highest adsorption capacity achieved was 0.95 mg·g^(−1).The flubendiamide adsorption mechanism by CMBC can be described with a pseudo-second-order kinetic model.The experiment data closely fit a Freundlich isotherm model(R^(2)=0.998),and the low residual sum of squares values demonstrate the high model applicability.In this study,we present a comprehensive overview of pesticides,alongside kinetic and isotherm model studies of flubendiamide adsorption by CMBC.We emphasize the potential of modified biochar to enhance environmental remediation applications.
基金Sponsored by the National Natural Science Foundation of China(Grant No.20271019 and 20576027), Natural Science Foundation of Heilongjiang Prov-ince(Grant No.B200504), Postdoctoral Foundationof Heilongjiang Province(Grant No.LBH-Z05066) and Education Department Foundation of Hei-longjiang Province(Grant No.11511270).
文摘Iron-based perovskite-type compounds modified by Ru were prepared through sol-gel process to study its catalytic activity of NOx direct decomposition at low temperature and evaluate the conversion of NO under the experimental conditions. The catalytic activity of La 0.9Ce 0.1Fe 0.8-nCo 0.2RunO3 （n=0.01,0.03,0.05,0.07,0.09）series for the NO, NO-CO two components, CO-HC-NO three components were also analyzed. The catalytic investigation evidenced that the presence of Ru is necessary for making highly activity in decomposition of nitric oxide even at low temperature（400 ℃）and La 0.9Ce 0.9Fe 0.75Co 0.2Ru 0.05O3 （n=0.05） has better activity in all the samples, the conversion of it is 58.5%. With the reducing gas（CO,C3H6）added into the gas, the catalyst displayed very high activity in decomposition of NO and the conversion of it is 80% and 92.5% separately.
基金supported by the Key Project of Science and Technology Department of Guizhou Province(No.ZK(2022)016)the Special Research Fund of Natural Science(Special Post)of Guizhou University(No.(2020)01)the Key Cultivation Program of Guizhou University(No.2019(08)).
文摘Antibiotic pollution has become a global eco-environmental issue.To reduce sulfonamide antibiotics in water and improve resource utilization of solid wastes,phosphogypsummodified biochar composite(PMBC)was prepared via facile one-step from distillers grains,wood chips,and phosphogypsum.The physicochemical properties of PMBCwere characterized by scanning electron microscope(SEM),Fourier transform infrared spectroscopy(FTIR),Zeta potential,X-ray diffraction(XRD),etc.The influencing factors,adsorption behaviors,and mechanisms of sulfadiazine(SD)and sulfamethazine(SMT)onto PMBC were studied by batch and fixed bed column adsorption experiments.The results showed that the removal rates of SD and SMT increased with the increase of phosphogypsum proportion,while decreased with the increase of solution pH.The maximum adsorption capacities of modified distillers grain and wood chips biochars for SD were 2.98 and 4.18 mg/g,and for SMT were 4.40 and 8.91mg/g,respectively,which was 9.0–22.3 times that of pristine biochar.Fixed bed column results demonstrated that PMBC had good adsorption capacities for SD and SMT.When the solution flow rate was 2.0 mL/min and the dosage of PMBC was 5.0 g,the removal rates of SD and SMT by modified wood chips biochar were both higher than 50%in 4 hr.The main mechanisms of SD and SMT removal by PMBC are hydrogen bonding,π-πdonor-acceptor,electrostatic interaction,and hydrophobic interaction.This study provides an effective method for the removal of antibiotics in water and the resource utilization of phosphogypsum.
基金supported by the National Natural Science Foundation of China(No.41472223)
文摘As an effective conventional absorbent, biochar exhibited limited adsorption ability toward small hydrophobic molecules. To enhance the adsorption capacity, a novel adsorbent was prepared by immobilizing nanoscale zero-valent iron onto modified biochar（MB） and then the elemental silver was attached to the surface of iron（Ag/Fe/MB）. It＇s noted that spherical Ag/Fe nanoparticles with diameter of 51 nm were highly dispersed on the surface of MB. As the typical hydrophobic contaminant, carbon tetrachloride was selected for examining the removal efficiency of the adsorbent. The removal efficiencies of carbon tetrachloride by original biochar（OB）, Ag/Fe, Ag/Fe/OB and Ag/Fe/MB were fully investigated. It＇s found that Ag/Fe/MB showed higher carbon tetrachloride removal efficiency, which is about 5.5 times higher than that of the OB sample due to utilizing the merits of high adsorption and reduction. Thermodynamic parameters revealed that the removal of carbon tetrachloride by Ag/Fe/MB was a spontaneous and exothermic process, which was affected by solution p H, initial carbon tetrachloride concentration and temperature. The novel Ag/Fe/MB composites provided a promising material for carbon tetrachloride removal from effluent.
基金supported by the Foundation of National Special Item on Water Resource and Environment (No.2014ZX07303003 and 2017ZX07603003)
文摘Low organic matter content and high heavy metal levels severely inhibit the anaerobic digestion(AD) of sewage sludge. In this study, the effect of added manganese oxidemodified biochar composite(MBC) on methane production and heavy metal fractionation during sewage sludge AD was examined. The MBC could increase the buffering capacity,enhance the methane production and degradation of intermediate acids, buffer the pH of the culture, and stabilize the sewage sludge AD process. The application of MBC positively impacted methane production and the cumulative methane yield increased up to 121.97%,as compared with the control. The MBC addition can improve metal stabilization in the digestate. An optimum MBC dose of 2.36 g was recommended, which would produce up to 121.1 L/kg volatile solids of methane. After the AD process, even though most of the metals accumulated in the residual solids, they could be transformation from the bio-available fractions to a more stable fraction. The total organic-and sulfide-bound and residual fraction content at a 3 g dose of MBC that is 0.12 g/g dry matter were 51.06% and 35.11% higher than the control, respectively. The results indicated that the application of MBC could improve the performance of AD and promote stabilization of heavy metals in sewage sludge post the AD process.
文摘Compost has been used to stabilise lead (Pb) in soil. However, compost contains a high level of dissolved organic matter (DOM) which may make Pb bioavailable in plant and thereby limiting its effectiveness and application. Addition of biochar to compost can reduce this effect. Rice husk (RH) and Cashew nut shell (CNS) biochars and compost-modified biochars were used in comparison to compost for stabilizing Pb in lead smelting slag (LSS)-contaminated soil (Pb = 18,300 mg/kg) in Nigeria. Efficiency of Pb stabilisation in control and amended soils was assessed using CaCl2 batch leaching experiment and plant performance. In pot experiments, maize plant was grown on the contaminated soil and on soil treated with minimum and optimum doses of the amendments singly and in combination for 6 weeks. Agronomical and chemical parameters of the plants were measured. CaCl2-extractable Pb in the untreated soil was reduced from 60 mg/kg to 0.55 mg/kg in RHB amended soils and non-detectable in other amended soils. RH-biochar/compost increased plant height, number of leaf and leaf area more than the others. Similarly, at minimum rate, it reduced root and shoot Pb by 91% and 86.0% respectively. Compost-modified rice husk biocharstabilised Pb in lead smelting slag contaminated soil reduced Pb plant uptake and improved plant growth. Lead stabilisation through the use of rice husk biochar with compost may be a green method for remediation of lead smelting slag-contaminated soil.
文摘In order to reduce the waste of resources and environmental pollution caused by excessive application of chemical fertilizers, improve the utilization rate of fertilizers, and promote the large-scale and high-quality development of the Chinese rose industry. In this experiment, corn stover biochar, phosphoric acid modified biochar and organic fertilizer were used as test materials, and the effects of mixed application of modified biochar and organic fertilizer on the growth and development of Chinese rose as well as soil physicochemical properties were investigated by using the method of pot planting test. The results showed that modified biochar with organic fertilizer had the most significant effect on the enhancement of soil pH, organic matter content and soil carbon-to-nitrogen ratio. After 120 d of planting, modified biochar with organic fertilizer had the most significant effect on the enhancement of plant height and crown width of Chinese rose;both organic fertilizer and modified biochar with organic fertilizer significantly increased the chlorophyll content of Chinese rose. The number of flowers and the number of branches were the highest in the modified biochar with organic fertilizer treatment. In conclusion, the application of modified biochar with organic fertilizer can better improve the soil pH, and increase the soil organic matter content and carbon-to-nitrogen ratio to change the biological traits of Chinese rose. The results of this study provide a theoretical basis for the reduction of chemical fertilizers and the resource utilization of agricultural wastes and guarantee the sustainable development of the cut flower industry.
文摘Two major problems facing agriculture at present are soil pollution and the disposal of solid wastes generated during plant growth. The method of preparing biochar from solid wastes produced by plants is a means of maximizing the use of resources to combat the problem of soil pollution. In this study, we did not choose straw in the traditional sense but the waste branches from grape pruning, which has higher lignin cellulose, as the raw material. The biochar derived from grape branches pyrolyzed at 300˚C for two hours was utilized as a raw material to prepare modified biochar with varying concentrations of phosphoric acid. The adsorption performance and mechanism of Cd<sup>2 </sup> were explored through experiments involving different concentrations, addition amounts, reaction times, kinetic analyses, and isothermal adsorption tests. The findings indicated that the optimal adsorption of Cd<sup>2 </sup> occurred with a 20% phosphoric acid concentration, achieving the highest adsorption rate of 84.62%. At a dosage of 10 g/L, the maximum adsorption capacity reached 7.02 mg/g. The adsorption kinetics and isothermal adsorption of Cd<sup>2 </sup> on biochar modified with 0.2% phosphoric acid (0.2 PB) closely followed the pseudo-first-order kinetics model (R<sup>2</sup> > 0.98) and the Freundlich model (R<sup>2</sup> > 0.97), respectively. This suggests that the adsorption process involves both physical and chemical mechanisms. SEM and FTIR analyses revealed that phosphoric acid modification primarily increased the biochar’s specific surface area and enhanced certain original functional groups. The adsorption process predominantly involved rapid ion diffusion and chemical adsorption, as confirmed by kinetic analysis and isothermal adsorption model analysis. In summary, the adsorption efficiency of 0.2 PB significantly improved, showing potential and feasibility for heavy metal remediation in soil. This supports the environmentally friendly concept of “treating waste with waste”.
基金The National Natural Science Foundation of China(No.52470216)the Natural Science Foundation of Jiangsu Province(No.BK20211175).
文摘Food waste,owing to its high organic content and moisture,offers a more scientifically sound resource utilization method compared to traditional treatment processes.This study presents a method to convert food waste into nitrogen-doped,modified hydrogel biochar modified food waste hydrogel biochar and investigates its effectiveness in adsorbing humic acid(HA).The modified biochar demonstrates superior adsorption capacity for HA compared to unmodified biochar.The adsorption follows the Langmuir isotherm model(R2=0.999),achieving a maximum adsorp-tion capacity of 49.5 mg/g with RL=0.0013-0.0051(0<RL<1).Furthermore,the adsorption process conforms to a pseudo-first-order model.The mechanism underlying HA adsorption involves the successful modification of food waste hydrogel biochar by 3-Aminopropyltriethoxysilane(APTES).This modification forms Si―R―NH_(3)^(+) on the biochar surface,which interacts with the COOH―groups in HA through hydrogen bonding and coordination bonds.Some unmodified APTES directly adsorbs onto the biochar surface,undergoing condensation and self-assembly to form ladder-like oligomeric siloxane polymers that enhance HA adsorption.
基金supported by the Natural Science foundation of the Jiangsu Higher Education Institutions(No.24KJB610019)the Scientific Research Foundation of Yancheng Teachers University(No.204060047)the Horizontal Topic Research“Developing the environmental remediation technology by acoustic catalysis”(No.203060199).
文摘Chlorite(ClO_(2)^(−)or COI)is used to establish the advanced reduction and oxidation process(AROP).The iron/biochar-based particles(iron-based hydrothermal carbon with hinge-like structure,FebHCs,20 mg/L)can be utilized to activate COI(2 mmol/L)to present selective oxidation in removing triphenylmethane derivatives(15 min,90%).The protonation(H+at~102μmol/L level)played a huge role(k-2nd=0.136c-H+−0.014(R^(2)-adj=0.986),and rapp=−0.0876/c-H++1.017(R^(2)-adj=0.996))to boost the generation of the active species(e.g.,high-valent iron oxidizing species(HVI=O)and chlorine dioxide(ClO_(2))).The protonation-coupled electron transfer promoted Fe-substances in Feb/HCs activating COI(the calculated kobs ranging from 0.066−0.285 min^(−1)).The form of ClO_(2) mainly attributed to proton-coupled electron transfer(1e/1H+).The HVI=O was generated from the electron transfer within the coordination complex.Moreover,carbon particles in FebHCs serve as the bridge for electron transfer.The above roles contribute to the fracture and formation of coordination-induced bonds between Lx-FeII/III and ClO_(2)^(−)at phase interface to form AROP.The ultrasonic(US)cavitation enhanced the mass transfer of active species in bulk solution,and the HVI=O and ClO_(2) attack unsaturated central carbon atoms of triphenylmethane derivatives to initiate selective removal.Furthermore,the scale-up experiment with continuous flow(k values of approximately 0.2 min^(−1),COD removal efficiency of approximately 80%)and the reactor with COMSOL simulation have also proved the applicability of the system.The study offers a novel AROP and new insights into correspondingly heterogeneous interface activation mechanisms.
基金supported by grants from the National Natural Science Foundation of China(31870420)Science and Technology Program of Guangdong Province(2121A0505030057).
文摘Nowadays,biochar is well recognized for its multiple promising effects on the soil quality and plant health.However,there are limited studies on the utilization of invasive plants for biochar production.In the present study,silicon(Si)-modified biochar was synthesized from Solidago canadensis L.,an invasive alien plant in southern China,at different pyrolysis temperatures(450,550,and 650℃).The role of biochar in controlling bacterial wilt,improving soil quality and plant health was assessed.The results revealed that Si-modified biochar had higher wilt suppressive effects than unmodified biochar.Si-modified biochar synthesized at 450℃was found to be the most effective in reducing the abundance of R.solanacearum in soil(66.0%)and the incidence rate of bacterial wilt(59.1%).The Si-modified biochar increased soil available Si(58.2%–147.8%),C/N ratio(85.8–105.0%),and cation exchange capacity(19.7–54.5%).Additionally,it also enhanced the abundance of beneficial bacteria in the soil,such as Bacillus(341.7%),Streptomyces(222.0%),Gaiellales(255.4%),and Gaiella(133.3%).These findings suggest that Si-modified biochar derived from the invasive plant Solidago canadensis L.holds promise as a soil additive for disease control.
基金supported by the National Natural Science Foundation of China(42077090)National Key Research and Development Program of China(2023YFD1902903)Key Science and Technology Research and Development Project of Hangzhou(202204T05).
文摘Carbon sequestration in farmland is an important pathway to alleviate global warming.Biochar has been considered an excellent material for soil carbon sequestration because of its high stability.How exogenous minerals and pyrolysis temperature regulate the priming effects(PEs)of biochar on soil organic carbon has rarely been studied,relative microbial mechanisms especially the roles of soil bacteria are far from known.Therefore,a series of biochar was prepared by pyrolysis using(13)^C isotope labelled rice straw at temperatures of 300,500,and 700℃with vermiculite modification(VBC300,VBC500,VBC700)and without modification(BC300,BC500,BC700).Incubation experiments were conducted to investigate the PEs of different biochar on the native organic carbon of two types of soil.Results showed that BC300,VBC300,and BC500 induced positive PE,VBC500,BC700,and VBC700 mainly induced negative PE in red soil.All biochar showed negative PE in paddy soil,with PE intensity order of 500℃>700℃>300℃.Biochar caused a shift in the bacterial phyla from copiotrophic to oligotrophic bacteria in red soil,whereas it shifted from the coexistence of copiotrophic and oligotrophic to copiotrophic in paddy soil over time.Biochar promoted the interaction among soil bacterial communities indicated by an increase in the edge number of bacterial networks.The correlation coefficient between PE and bacteria networks’edge number was 0.626 and 0.909 in red soil and paddy soil,respectively.Vermiculite modification weakened the promotion effect of biochar on bacterial community interaction and thus was beneficial for carbon sequestration,especially in red soil.VBC700 had excellent carbon sequestration potential in red soil,whereas that was VBC500 in paddy soil.
文摘Arsenic(As)is a known carcinogen and naturally occurring semi-metal in soils and in the Earth's crust.Contamination of soils and water with As poses a serious threat to millions of people worldwide due to its health hazards and toxicological properties.Hence,devising novel and efficient methods for remediation of contaminated areas has attracted a great deal of interest across the globe.In this study,we investigated the usefulness of synthetic birnessite,goethite,hexadecylpyridinium chloride-modified montmorillonite(HDPC-M),hexadecylpyridinium bromide-modified zeolite(HDPB-Z),and lanthanum(La)-doped magnetic biochar produced from eucalyptus bark(La-Euchar)as adsorbents at 10%dosage for As stabilization in a soil spiked with 1000 mg kg^(-1)As.The effectiveness of the above adsorbents in As immobilization in soil was assessed using single-step extractions with 2 mol L^(-1)HNO_(3)and deionized water,the simplified bioaccessibility extraction test(SBET)method,and sequential extraction with the modified Community Bureau of Reference(BCR)method.Application of the adsorbents shifted the exchangeable fraction of As to more recalcitrant fractions and dramatically reduced the exchangeable fraction by 6%-99%and the extractable amounts with HNO_(3),deionized water,and SBET method by 30%-92%,17%-95%,and 12%-90%,respectively,compared to the unamended control.The immobilizing effects of adsorbents on As decreased in the sequence of birnessite>La-Euchar>goethite>HDPB-Z>HDPC-M.Birnessite exhibited great affinity for As and drastically reduced As extractability by more than 90%in all single extractions.The results revealed that HDPC-M,HDPB-Z,La-Euchar,birnessite,and goethite are promising immobilizing agents for in situ stabilization of As in terrestrial environments.
